Field of the Invention -- The invention relates generally to motor vehicles and more specifically to self-contained propulsion systems for the human body. A muscle assisting device for cross-country skiing is disclosed.
Description of the Prior Art -- Ground travel across snow has always presented a problem with regard to the low friction between the snow surface and the foot of the traveller. The ski takes advantage of this low friction by allowing rapid controlled travel along downslopes, but requires that unnatural muscle movement be employed when long stretches of level ground or up-hill terrain are encountered. Cross-country skiiers have developed many techniques for applying positive muscle power through the skis, often modifying the ski through special surfaces thereon to prevent backward sliding when the traveller is attempting to ascend a slope.
Mechanical aids for the skier have also been developed. Patent 3,645,348 to Thompson teaches a tractor tread device that can be used on the rear of a ski to propel the wearer up-hill. Patent 2,509,603 to Marin teaches a jet pack that can thrust the wearer in a desired direction. These inventions attempt to mechanize the sport of skiing, converting the ski into a minivehicle that retains the ability to coast down a hill. Yet, many persons seek and enjoy the activity of manually propelling themselves on skis, but could increase their mobility if given means to aid their muscles during long periods of exertion. The present invention provides a mechanically powered aid for the skier who wishes to decrease the fatigue of cross-country skiing while retaining the benefits of actively participating self-propulsion.